31 research outputs found
Beta-keratins of the crocodilian epidermis: composition, structure, and phylogenetic relationships
No full textNucleotide and deduced amino acid sequences of three beta-keratins of Nile crocodile scales are presented. Using 5'- and 3'-RACE analysis, two cDNA sequences of 1 kb (Cr-gptrp-1) and 1.5 kb (Cr-gptrp-2) were determined, corresponding to 17.4 and 19.3 kDa proteins, respectively, and a pI of 8.0. In genomic DNA amplifications, we determined that the 5'-UTR of Cr-gptrp-2 contains an intron of 621 nucleotides. In addition, we isolated a third gene (Cr-gptrp-3) in genomic DNA amplifications that exhibits seven amino acid differences with Cr-gptrp-2. Genomic organization of the sequenced crocodilian beta-keratin genes is similar to avian beta-keratin genes. Deduced proteins are rich in glycine, proline, serine, and tyrosine, and contain cysteines toward the N- and C-terminal regions, likely for the formation of disulfide bonds. Prediction of the secondary structure suggests that the central core box of 20 amino acids contains two beta-strands and has 75-90% identity with chick beta-keratins. Toward the C-terminus, numerous glycine-glycine-tyrosine and glycine-glycine-leucine repeats are present, which may contribute to making crocodile scales hard. In situ hybridization shows expression of beta-keratin genes in differentiating beta-cells of epidermal transitional layers. Phylogenetic analysis of the available archosaurian and lepidosaurian beta-keratins suggests that feather keratins diversified early from nonfeather keratins, deep in archosaur evolution. However, only the complete knowledge of all crocodilian beta-keratins will confirm whether feather keratins have an origin independent of those in bird scales, which preceded the split between birds and crocodiles
Beta-keratins of turtle shell are glycine-proline-tyrosine rich proteins similar to those of crocodilians and birds
No full textThis study presents, for the first time, sequences of five beta-keratin cDNAs from turtle epidermis obtained by means of 5'- and 3'-rapid amplification of cDNA ends (RACE) analyses. The deduced amino acid sequences correspond to distinct glycine-proline-serine-tyrosine rich proteins containing 122-174 amino acids. In situ hybridization shows that beta-keratin mRNAs are expressed in cells of the differentiating beta-layers of the shell scutes. Southern blotting analysis reveals that turtle beta-keratins belong to a well-conserved multigene family. This result was confirmed by the amplification and sequencing of 13 genomic fragments corresponding to beta-keratin genes. Like snake, crocodile and avian beta-keratin genes, turtle beta-keratins contain an intron that interrupts the 5'-untranslated region. The length of the intron is variable, ranging from 0.35 to 1.00 kb. One of the sequences obtained from genomic amplifications corresponds to one of the five sequences obtained from cDNA cloning; thus, sequences of a total of 17 turtle beta-keratins were determined in the present study. The predicted molecular weight of the 17 different deduced proteins range from 11.9 to 17.0 kDa with a predicted isoelectric point of 6.8-8.4; therefore, they are neutral to basic proteins. A central region rich in proline and with beta-strand conformation shows high conservation with other reptilian and avian beta-keratins, and it is likely involved in their polymerization. Glycine repeat regions, often containing tyrosine, are localized toward the C-terminus. Phylogenetic analysis shows that turtle beta-keratins are more similar to crocodilian and avian beta-keratins than to those of lizards and snakes
Forty keratin-associated b-proteins (b-keratins) form the hard layers of scales, claws, and adhesive pads in the green anole lizard, Anolis carolinensis
No full textUsing bioinformatic methods we have detected the genes of 40 keratin-associated b-proteins
(KAbPs) (b-keratins) from the first available draft genome sequence of a reptile, the lizard Anolis
carolinensis (Broad Institute, Boston). All genes are clustered in a single but not yet identified
chromosomal locus, and contain a single intron of variable length. 50-RACE and RT-PCR analyses
using RNA from different epidermal regions show tissue-specific expression of different
transcripts. These results were confirmed from the analysis of the A. carolinensis EST libraries
(Broad Institute). Most deduced proteins are 12–16 kDa with a pI of 7.5–8.5. Two genes encoding
putative proteins of 40 and 45 kDa are also present. Despite variability in amino acid sequences,
four main subfamilies can be described. The largest subfamily includes proteins high in glycine, a
small subfamily contains proteins high in cysteine, a third large subfamily contains proteins high in
cysteine and glycine, and the fourth, smallest subfamily comprises proteins low in cysteine and
glycine. An inner region of high amino acid identity is the most constant characteristic of these
proteins and maps to a region with two to three close b-folds in the proteins. This b-fold region is
responsible for the formation of filaments of the corneous material in all types of scales in this
species. Phylogenetic analysis shows that A. carolinensis KAbPs are more similar to those of other
lepidosaurians (snake, lizard, and gecko lizard) than to those of archosaurians (chick and crocodile)
and turtles
Forty Keratin-Associated beta-Proteins (beta-Keratins) Form the Hard Layers of Scales, Claws, and Adhesive Pads in the Green Anole Lizard, Anolis carolinensis
No full textUsing bioinformatic methods we have detected the genes of 40 keratin-associated beta-proteins (KAbetaPs) (beta-keratins) from the first available draft genome sequence of a reptile, the lizard Anolis carolinensis (Broad Institute, Boston). All genes are clustered in a single but not yet identified chromosomal locus, and contain a single intron of variable length. 5'-RACE and RT-PCR analyses using RNA from different epidermal regions show tissue-specific expression of different transcripts. These results were confirmed from the analysis of the A. carolinensis EST libraries (Broad Institute). Most deduced proteins are 12-16 kDa with a pI of 7.5-8.5. Two genes encoding putative proteins of 40 and 45 kDa are also present. Despite variability in amino acid sequences, four main subfamilies can be described. The largest subfamily includes proteins high in glycine, a small subfamily contains proteins high in cysteine, a third large subfamily contains proteins high in cysteine and glycine, and the fourth, smallest subfamily comprises proteins low in cysteine and glycine. An inner region of high amino acid identity is the most constant characteristic of these proteins and maps to a region with two to three close beta-folds in the proteins. This beta-fold region is responsible for the formation of filaments of the corneous material in all types of scales in this species. Phylogenetic analysis shows that A. carolinensis KAbetaPs are more similar to those of other lepidosaurians (snake, lizard, and gecko lizard) than to those of archosaurians (chick and crocodile) and turtles
Beta-keratins of the crocodilian epidermis: composition, structure, and phylogenetic relationships
No full textBeta keratins of turtle shell are glycine-proline-tyrosine rich proteins similar to those of crocodilians and birds
No full textÉtude in vitro de la durée d écoulement de solutions antibiotiques preparées dans des diffuseurs portables élastomériques (effet du stockage au froid pendant trois à sept jours)
No full textLa prise en charge des patients atteints de mucoviscidose en région Rhône-Alpes s organise comme partout en France autour des Centres de Ressources et de Compétences pour la Mucoviscidose (CRCM) mais également de manière complémentaire avec la participation du réseau EMERA (Ensemble contre la Mucoviscidose en Rhône-Alpes). Le réseau EMERA propose notamment l organisation des cures d antibiotiques intraveineuses à domicile elles-mêmes préparées de manière centralisée dans des diffuseurs portables élastomériques par la pharmacie à usage à intérieur du CHU de Grenoble de même que celle des Hospices Civils de Lyon. Néanmoins, il a été constaté que les durées de perfusion de ces diffuseurs étaient très souvent supérieures aux durées de perfusion nominales indiquées par leurs fabricants. La pharmacie du CHU de Grenoble s est donc proposée d investiguer les différentes causes potentiellement à l origine de cette non-conformité. Les résultats de l étude in vitro ont mis en évidence l impact : 1. du délai entre remplissage du diffuseur et écoulement de la solution, 2. du stockage des diffuseurs au froid, 3. de la concentration en antibiotique et donc de la viscosité de la solution à administrer. Il est donc essentiel que les équipes soignantes aient connaissance des différents facteurs pouvant conduire à un allongement de la durée des perfusions réalisées au moyen de ces dispositifs de perfusion. Lorsque les délais de perfusion supplémentaires restent acceptables, il convient d en informer le patient et de relativiser cet allongement par rapport aux avantages nombreux que confèrent ces dispositifs pour la prise en charge à domicile.GRENOBLE1-BU Médecine pharm. (385162101) / SudocSudocFranceF
Ancient transposable elements transformed the uterine regulatory landscape and transcriptome during the evolution of mammalian pregnancy
No full textA major challenge in biology is determining how evolutionarily novel characters originate; however, mechanistic explanations for the origin of new characters are almost completely unknown. The evolution of pregnancy is an excellent system in which to study the origin of novelties because mammals preserve stages in the transition from egg laying to live birth. To determine the molecular bases of this transition, we characterized the pregnant/gravid uterine transcriptome from tetrapods to trace the evolutionary history of uterine gene expression. We show that thousands of genes evolved endometrial expression during the origins of mammalian pregnancy, including genes that mediate maternal-fetal communication and immunotolerance. Furthermore, thousands of cis-regulatory elements that mediate decidualization and cell-type identity in decidualized stromal cells are derived from ancient mammalian transposable elements (TEs). Our results indicate that one of the defining mammalian novelties evolved from DNA sequences derived from ancient mammalian TEs co-opted into hormone-responsive regulatory elements distributed throughout the genome.Vincent J. Lynch, Mauris C. Nnamani, Aurélie Kapusta, Kathryn Brayer, Silvia L. Plaza, Erik C. Mazur, Deena Emera, Shehzad Z. Sheikh, Frank Grützner, Stefan Bauersachs, Alexander Graf, Steven L. Young, Jason D. Lieb, Francesco J. DeMayo, Cédric Feschotte, Günter P. Wagne
Modelling of CO2 and green-house gases (GHG) miscibility and interactions with oil to enhance the oil recovery in gas flooding processes
No full text1. Objective:
The objective of this research has been to develop more reliable models to predict the miscibility and interactions between CO₂ or green-house gas (GHG) and oil (dead and live oils) over a wider range of conditions, based on data from different site sources, considering all the major variables affecting each modelled parameter, and for different injected gas compositions. The Genetic algorithm (GA), an artificial intelligence technique based on the Darwinian theory of evolution that mimics some of the natural processes in living organisms, was used to develop these models, based on GA software that has been developed in this work (as a modelling technique). While applications of GA have been used recently in the mathematical and computer sciences, its applications in the petroleum engineering, especially EOR research, have been limited. 2. Motivation to Investigate the Potential of GA-based Models: The detrimental effects of CO₂ and/or GHG emissions from various industrial and human/activity sources on the environment are a major concern worldwide. This has resulted in an intensive global R&D effort to lower or mitigate the damaging impact of GHG on the environment. One potentially attractive and effective means of lowering the GHG emissions could be to capture them from their major sources of emissions and then sequester them in depleted oil and gas reservoirs while also enhancing oil recovery. Typically, a GHG stream, also referred to as "flue gas", contains high percentages of CO₂ in addition to other gases, notably, N₂, NOₓ and SOₓ. The presence of high CO₂ content in the flue gas, in particular, could make this option potentially viable, provided the miscibility and interaction properties between the injected gas and reservoir fluids are favorable. Therefore, it is critical to ascertain the likely miscibility and interactions parameters between the injected gas (CO₂ or flue gas) and oil at different conditions to determine the optimal miscibility and interaction conditions that contribute to oil viscosity reduction and oil swelling. They in turn enhance oil recovery through improved gas flooding process performance due to higher oil mobility, volumetric sweep efficiency, and relative permeability to oil. Often miscibility and interactions between injected gases and oils are established through "experimental methods", "new mathematical models" based on phase equilibria data and equations of state (EOS), and available "published models". Experimental methods are time-consuming and costly. Moreover, they can handle only limited conditions. Mathematical models require availability of a considerable amount of reservoir fluid composition data, which may not be available most of the time. Although, the published models are simpler and faster to use, one must however recognise that most of these models were developed and validated based on limited data ranges from site-specific conditions. Therefore, their applications cannot be generic. Another noteworthy point is that most of the interactions models have been developed using dead oil data and pure CO₂ as an injected gas. Hence, they do not perform well for a wider range of live oils, as well as injected flue gases, which contain different components besides CO₂. Consequently, there is a need to have more reliable miscibility and interaction models, which can handle a much wider range of conditions and different data sources. Also, these models should be able to consider all the major variables, different injected gas compositions, and live oil in addition to dead oil. 3. GA-based Models Developed in This Research: -- GA-based model for more reliable prediction of minimum miscibility pressure (MMP) between reservoir oil and CO₂: This model recognised the major variables affecting MMP (reservoir temperature, MWc₅₊ , and volatiles and intermediates compositions). It has been successfully validated with published experimental data and compared to common models in the literature. It is noted that GA-based CO₂-oil MMP offered the best match with the lowest error and standard deviation. -- GA-based flue gas-oil MMP model: For this model, the MMP was regarded as a function of the injected gas solubility into oil, which in turn is related to the injected gas critical properties (pseudocritical temperature and pressure) besides reservoir temperature and oil composition. A critical temperature modification factor was also used in developing this model. The GA-based model has also been successfully validated against published experimental data and compared to several models in the literature. It yielded the best match with the lowest average error and standard deviation. Moreover, unlike other models, it can be used more reliably for gases with higher N₂ (up to 20 mole%) and different non-CO₂ components (e.g., H₂S, N₂, SOₓ, O₂, and C₁-C₄) with higher ratio (up to 78 mole%). -- GA-based CO₂-oil physical properties models: These models have been developed to predict CO₂ solubility, impact on the oil swelling factor, CO₂-oil density, and CO₂-oil viscosity for both dead and live oils. These models recognised the major variables that affect each physical property and also properly address the effects of CO2 liquefaction pressure and oil molecular weight (MW). These models have been successfully validated with published experimental data and have been compared against several widely used models. The GA-based CO₂-oil properties models yielded more accurate predictions with lower errors than other models that have been tested. Furthermore, unlike the other tested models, which are applicable to only limited data ranges and conditions, GA-based models can be applied over a wider data range and conditions. -- GA-based flue gas-oil physical properties models: These models predict flue gas-oil properties such as, flue gas solubility, impact on the oil swelling factor, and flue gas-oil density and viscosity while recognising all the major variables affecting each property. Also, the GA-based models recognised the different injected flue gas compositions. These models have been successfully validated with published experimental data and have also been compared against other commonly reported CO₂-oil models, which are often used for flue gas-oil physical properties prediction. The GA-based models consistently yielded a lower prediction error than the models that have been tested. Furthermore, unlike other models, which are applicable only over limited data ranges and conditions, GA-based models can be valid over a wider range of data under various conditions. All the above-mentioned models, developed in this research, are particularly useful when experimental data are lacking and the project financial situation is a concern. In addition, these models can be useful as a fast track gas flooding project screening guide. Also, they can easily be incorporated into a reservoir simulator for CO₂ or flue gas flooding design and simulation. Furthermore, they can serve as yet another useful tool to design optimal and economical experimental test protocols to etermine the miscibility and interactions between the injected CO₂ or flue gas and oils in gas flooding processes.Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2006
